Piezoelectric (piezoelectric DOD inkjet)

Piezoelectric (piezoelectric DOD inkjet)

Most commercial and industrial inkjet printers and some consumer printers (those produced by Epson) use a piezoelectric material in an ink-filled chamber behind each nozzle instead of a heating element. When a voltage is applied, the piezoelectric material changes shape, which generates a pressure pulse in the fluid forcing a droplet of ink from the nozzle. Piezoelectric (also called Piezo) inkjet allows a wider variety of inks than thermal inkjet as there is no requirement for a volatile component, and no issue with kogation (buildup of ink residue), but the print heads are more expensive to manufacture due to the use of piezoelectric material (usually PZT, lead zirconium titanate). A drop-on-demand process uses software that directs the heads to apply between zero to eight droplets of ink per dot, only where needed.
Piezo inkjet technology is often used on production lines to mark products - for instance the "use-before" date is often applied to products with this technique; in this application the head is stationary and the product moves past. Requirements of this application are high speed, a long service life, a relatively large gap between the print head and the substrate, and low operating cost.
As of June 2009, the fastest cut-sheet inkjet printer on the market is the RISO ComColor 9050, which prints 146 USLetter and 150 A4 full-color pages per minute in both one-sided and two-sided printing modes.^[5][6]
Recent developments of piezo inkjet technology are extending the technique from printing into manufacturing processes. The newest of these technologies is to deposit layers of plastic material as digital embossing over the top of printed works.^[7]